Bubbles

Hey everyone, hows the weekend going? Hope everyone had a good good friday. I sure did. Played some ping pong and some tennis. Ok, so the other day, I helped my brother wash his car. Ever since I was little, I've always wondered why I saw such an assortment of colors on those thin bubbles from soap. After this chapter about interference, I now know why. Since the thin bubble is an example of thin-film, I can talk about thin-film interference. Some light reflects off the surface of the bubble, and other light rays reflect off the inside of the bubble. Since the light ray is entering a heavier medium with a larger index of refraction, it causes the light ray to experience a 180 degree phase change. As a result, when the light rays interfere at this area, there is destructive interference, and I see dark spots. However, at other places, when the phase difference of the light waves are zero or multiples of 360 degrees, the troughs and crests of each light wave match with the troughs and crests of other waves, causing constructive interference. Thus, I see bright spots on the bubble. At these brights spots, I can see an assortment of colors because it depends on the fringe number. At different fringe numbers, the light waves have different wavelengths, so I could see many different colors on the bubble.